view src/core/ngx_crc.h @ 336:1c519aff5c0c NGINX_0_6_12

nginx 0.6.12 *) Change: mail proxy was split on three modules: pop3, imap and smtp. *) Feature: the --without-mail_pop3_module, --without-mail_imap_module, and --without-mail_smtp_module configuration parameters. *) Feature: the "smtp_greeting_delay" and "smtp_client_buffer" directives of the ngx_mail_smtp_module. *) Bugfix: the trailing wildcards did not work; bug appeared in 0.6.9. *) Bugfix: nginx could not start on Solaris if the shared PCRE library located in non-standard place was used. *) Bugfix: the "proxy_hide_header" and "fastcgi_hide_header" directives did not hide response header lines whose name was longer than 32 characters. Thanks to Manlio Perillo.
author Igor Sysoev <http://sysoev.ru>
date Fri, 21 Sep 2007 00:00:00 +0400
parents fbf2b2f66c9f
children d0f7a625f27c
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/*
 * Copyright (C) Igor Sysoev
 */


#ifndef _NGX_CRC_H_INCLUDED_
#define _NGX_CRC_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


/* 32-bit crc16 */

static ngx_inline uint32_t
ngx_crc(u_char *data, size_t len)
{
    uint32_t  sum;

    for (sum = 0; len; len--) {

        /*
         * gcc 2.95.2 x86 and icc 7.1.006 compile
         * that operator into the single "rol" opcode,
         * msvc 6.0sp2 compiles it into four opcodes.
         */
        sum = sum >> 1 | sum << 31;

        sum += *data++;
    }

    return sum;
}


#endif /* _NGX_CRC_H_INCLUDED_ */